The Houston Texans' due diligence on their hunt for a rookie quarterback continues this month with visits from Central Florida's Blake Bortles on April 15-16, and Texas A&M's Johnny Manziel on April 21-22.

With 32 days to go before the NFL draft begins with the Texans' No. 1 overall pick, one of the draft's most intriguing questions -- and certainly, one of its pivotal points in terms of how the earliest picks will fall -- is whether Houston will use the top pick on a quarterback. The trio of new head coach Bill O'Brien, general manager Rick Smith and quarterbacks coach George Godsey attended each of the pro-day performances of Manziel, Bortles and Louisville quarterback Teddy Bridgewater. Now comes confirmation of the Bortles and Manziel visits to the club's facility from Houston Chronicle NFL writer John McClain, via Twitter.